CTA時代におけるTeVブレーザー探査井上芳幸 (京大, 学振特別研究員 DC1)
共同研究者：戸谷友則（京大）
森正樹（立命館）

CTA-Japan kick-off meeting @ Jan. 9th, 20101

What is BLAZAR?

SED Sequence

49Blazar
LogLog(νL10 10νi[erg/s])iL(erg s-1)

48
47
46
45
44
43

Synchrotron

InverseCompton
GeV

42
41-5

http://www.nasa.gov/

0510Log10 Ea (eV) [eV])
Log10 (Energy(Fossati+’97,’98; Kubo+’98; Donato+’01, but see also Padovani+’07)2

Current TeV Blazars

http://www.mppmu.mpg.de/~rwagner/sources/~25 TeV blazars/~100 TeV sources

3

TeV Blazars Survey by CTA

High energy phenomena around supermassive black holes.
Statistical analysis of TeV blazars✓AGN population
Constraints on Extragalactic Background Light (EBL)✓Star & Galaxy formation historyBlazar Survey Method1)Blank Field Sky Survey (Extragalactic version of the Galactic
plane survey by H.E.S.S.).
2)Following up other wavelength observations (e.g. Fermi).

• Which is better for CTA ?
• Gamma-ray luminosity function and SED are required.

4New Blazar Gamma-ray Luminosity Function(YI & Totani ’09)
Basic assumptions for blazar GLF construction•Blazar SED sequence.
•AGN X-ray Luminosity Function (Ueda+’03:hereafter U03).
Assuming “Ljet, bol ∝Ldisk, X “.

Constraining GLFs from EGRET data.
1.8

Redshift Distribution

0.8

1.6
1.2
1
0.8

0.7
U03(q)
U03(q,γ1)
H05(q)
H05(q,γ1)
EGRET blazars

0.6

0.5
0.4
0.3

0.4

0.2

0.2

0.1

00
0.01

0.1
Redshift
Redshift z z

U03(q)
U03(q,γ1)
H05(q)
H05(q,γ1)
EGRET blazars

0.6

dN/d(log10 Lγγ))
dN/log(LdN/d(log10 z)
dN/log(z)1.4

Luminosity Distribution

14344454647
48
log(Llog10 (L[erg s-1])γ γ[erg/s])

4950
5Cosmic X-ray and Gamma-ray Backgroundin the Fermi era
2-2 -1 2 -1 -1
E2E2dN/dE(MeV/cm/s/sr)
dN/dE (MeV cm s MeVsr )10-1

Blazar: U03 (q, a1)
Non-blazar (K=3.5): ITU08
Non-blazar (K=3.8): ITU08
Blazar + Non-blazar (K=3.5)
Blazar + Non-blazar (K=3.8)
EGRET (S98)
EGRET (S04a)
EGRET (S98+S08)
Fermi

10-2

10-3

non-blazar
AGNs(YI+08)

Fermi Data from
TeV conf.@0907

Blazars ( YI&TT09)
10-4
10-2

X-ray
10-1

MeV100GeV
101102103

PhotonEnergy(MeV)
Energy(MeV)

Our prediction matched with theFermi data very well.

104

105

106

YI & TT 09
arXiv:0810.3580
6Incorporating TeV blazars data in SED sequence1044

New SED sequencemodel taking into
account nearby TeV
blazars data.

1042
Mrk 421

Mrk 501

1ES 2344+514

Mrk 180

1ES 1959+650

BL LacPKS 2005-489

RGB J0152+017

W Comae

1040
1046
1044
1042
1040
1046

A new GLF with thisSED model.

1044
1042
1040
1046

Predictions for Fermi are
not so different from IT09.

1044
1042
PKS 2155-304

1040
1046

H 1426+428
10-5

1044

100

105

Energy [eV]1ES 0806+524
1010

10-5

100

105

Energy [eV]

1010

4210

This paper
IT09

1ES 0229+20

40

10

10-5

100

105

Energy [eV]1010

We adopt the EBLmodel from Totani &Takeuchi ’02.

New model : ~720
blazars for 1-year1046
surveyνLν [erg/s]

νLν [erg/s]

νLν [erg/s]

νLν [erg/s]

νLν [erg/s]νLν [erg/s]

1046

1044

IT09 : ~750 blazars for1042
1-year survey
1040

10-5

TeV Blazar Survey-12dN/dE)
2-2 -2
N(>EN (>EdFa/dE )[deg[deg ] ]10-1
10Expected Fermi
blazars
Expected Fermi
blazars

Expected Fermi blazars

Expected Fermi blazars-210-210300GeV
30 GeV
30GeV-3-3
1010CTA

CTA

CTA

CTA-4-4
1010100 GeV
100GeV

CTA

CTA

H.E.S.S.
-5

10-5
10-1310-12-11-10-9-1310101010 10
E2 dFa/dE (30GeV) [erg cm-2 s-1]-110-1
10

H.E.S.S.

-12

Expected Fermi blazars-21010-2

HAWC
HAWC

-310-310-410-410-510-51010-14-11

1 TeV

1TeV-10-9-1410101010 10
E2 dFa/dE (100GeV) [erg cm-2 s-1]

Expected Text
Fermi blazars-61010-6

H.E.S.S.

H.E.S.S.

-61010-62-2-2
N(>EN2dN/dE)(>E dFa/dE [deg) [deg ] ]300 GeV

CTA
CTA

Text blazars
Expected Fermi

HAWC
HAWC

10TeV
10 TeVTibet

H.E.S.S.
H.E.S.S.

CTA
CTA-13-12-11-1010101010
E2 dFa/dE (300GeV) [erg cm-2 s-1]

x-axis : E2dN/dE [erg/cm2/s]
for each energy band
Unabs
unabs
abs
Abs
Fermi: unabs
Fermi:unabs
Fermi: abs
Fermi:Abs

H.E.S.S.

Text
H.E.S.S.

10-13
10-12
10-11
10-1010-14
E2 dFa/dE (1TeV) [erg cm-2 s-1]

10-13
10-12
10-11
10-10
E2 dFa/dE (10TeV) [erg cm-2 s-1]

CTA, H.E.S.S. : 50 hr
HAWC : 1 year
8TeV Blazar Survey @300 GeV
10-1

N(>E2dN/dE) [deg-2]

10-2
10-3
10-410-510-6

Blank field sky
survey~1 blazar / 200deg2.
FoV of CTA is ~6deg2.
Unrealistic to doa blind field skysurvey.
Following up Fermi
blazars is morepromising.

Counts of Fermi blazars detectable by CTA
N(>Flux) [(4πsr)-1]

103
10210110-1

N(>Flux) [(4πsr)-1]

103
10210110-110

Counts of Fermi blazars detectable by CTA@300GeV

N(>Flux) [(4πsr)-1]

103Fermi 1-year

102

200 hr observation will
give ~80 TeV blazarsamples.
How to follow upefficiently?
Fermi gives flux(>100 MeV),redshift, and photonindex.

10110-1Flux(>100MeV) [photons cm-2 s-1]

Estimate TeV flux
from these data andEBL optical depth.
11Extragalactic Background
Light (EBL) Determination

12

Constraint on EBL from TeV obs.
It is difficult to observe
EBL directly.
TeV obs. is a new probeof EBL.
γ(TeV)+γ(EBL)→e++ e3C279(z~0.5) by MAGIC
is the highest redshift.
We constrain EBL byassuming an intrinsic
spectrum for each blazar.
Aharonian+’0613

Is it possible to detect TeV blazars aroundzτ with high significance?
100N (> E2 dFa/dE) [(4/ sr)-1]

zo/2 < z <2×zo
100 GeV300 GeV
1 TeV10 TeV10zτ is the redshift whereτ = 1.
Current TeV telescopes
constrains EBL with 5σ detection.
50 hr observationaltime by CTA will make86-σ for 300 GeV

11000-σ for 1 TeV
10-14

10-13

210-12-2 -1

E dFa/dE [erg cm s ]

10-11

10-10

8-σ for 10 TeV

Constraining the EBL models
from z-distribution
Difficult to detect high-z
blazars due to the EBL
absorption.

Clear Cut-off
due to EBL

A clear cut-off appears
in the z-distribution ofTeV blazars.
It might be possible toconstrain EBL from thiscut-off.

The expected number of TeVblazars around zτ.
To construct 30 TeV
blazars samples
around zτ, therequired observationaltime is
50 hr for 300 GeV,
30 hr for 1 TeV,
impossible for 10TeV.

Summary
Extragalactic blank field sky survey is inefficient.
~1 blazar / 200 deg2.
Following up Fermi blazars is efficient.
CTA will detect ~80 blazars with 200 hr obs. time
@ 300 GeV
CTA will detect blazars around zτ with higher
significance than current IACTs did.
Redshift distribution of TeV blazars will be acomplementary way to constrain EBL.
e.g. ~50 hr obs.time @ 300 GeV is required todo this new EBL constraint method.